Months before slaughtering beloved psychologist Dr. Kathryn Faughy, 56, in her East 79th Street office in 2008, Tarloff was notorious at the Forest View Center for Rehabilitation and Nursing in Queens.

He liked to get into bed and laying side by side with his wheelchair-bound mom, Beatrice, sometimes kissing her on the mouth, according to testimony. His defense hopes to prove he’s not guilty by reason of insanity.Tarloff faces life in prison if convicted, and an indeterminate institutionalization in a secure psychiatric jail if found not guilty by reason of insanity.

Tarloff has told cops and shrinks that God had directed him to rob Faughey’s colleague, Dr. Kent Shinbach, so he could use the cash to rescue his mother and take her to Hawaii.

But there was much to damage his insanity claim as well. Tarloff used the nursing home as a personal restaurant and piggy bank, staff testified — routinely stealing food from patients’ trays and withdrawing $100 or more at a time from his mother’s accounts.

Confronted, the filthy, disheveled Tarloff sometimes turned violent and loud — cursing, flailing his arms, and once tipping over an urn of hot coffee, staff told jurors. He’d been arrested for assaulting one staffer, and was barred from seeing his mother at all at the time of the killing.

Jurors and Faughey’s family members also watched grim-faced as a coroner described the more than a dozen mallet blows to Faughey’s head, and the to-the-hilt thrusting of a knife into her upper chest.

Faughey’s head injuries and stab wound were so separately serious, it could not be determined if her death resulted from the brain damage, the loss of blood, or a combination of the two, a coroner testified.

Prosecutors are expected to present the final witnesses of their direct case today, followed by the defense insanity case and the DA’s rebuttal case.